ELEKIT TU-8400 SE Tube Amplifier - Standard opts, With assembly

The TU-8400 is a pentode single-ended power amplifier built to work easily with a wide range of common octal-based output tubes. Spec-wise it sits between the long-popular TU-8200 and its bigger sibling, the TU-8850. Active automatic bias adjustment enables switching between HIGH and LOW operating modes to accommodate different power tubes. HIGH mode supports the 6L6 family, KT88, KT90, EL34 (6CA7), 5881, 6550 and more, and thanks to the high-current-capacity power transformer, KT120, KT150 and KT170 as well. LOW mode works with 6V6, 6F6 and similar types.

Technical specification:
- Voltage amp tube: 12AX7 (ECC83, 7025) x 1
- Output tubes: [HIGH mode]: 6L6 series, 5881, 7581, KT66, KT77, EL34 (6CA7), WE350B, 6550, KT88, KT90, etc. KT120, KT150, KT170, etc. can also be mounted, though the safety cover will not be possible to be installed., [LOW mode]: 6V6, 6F6, etc.
- Circuit configuration: Output stage A-class, Single-ended, Active Automatic BIAS (low-dissipation automatic biasing), AC heater power, B-power : MOSFET ripple filter (right and left channel independently, with fuse), Internal preamp at INPUT-2 : Preamp with OPamp (NJM2068DD)
- Max. output: [HIGH mode]: 2 x 9,8 W (KT170), 2 x 8,6 W (KT88), 2 x 8 W (EL34), 2 x 7 W (6L6), [LOW mode]: 2 x 3,3 W (6V6), 2 x 2,6 W (6F6), Measured on UL mode, 8 Ω load, THD 10 %
- Rated input: [INPUT-1]: 850 mV RMS, [INPUT-2]: 225 mV RMS, (in HIGH mode, UL, EL34)
- Frequency response: 20 – 50000 Hz (-3 dB, UL)
- Residual noise: 27 μV RMS (IHF-A, 8 Ω load, UL, HIGH)
- Input terminals: [INPUT-1]: RCA jack (back side), input resistance approx. 50 ㏀, [INPUT-2]: 3,5mm 3-pole mini jack, input resistance approx. 12 ㏀
- Output terminals: Biding terminals, gold plated, banana plugs compatible.
- Headphone output: 3-pole standard (diameter 6,3 mm) jack
- Speaker impedance: 4 – 16 Ω
- Heapdhone impedance: 8 – 600 Ω (corresponds to high impedance headphones as well), unbalanced
- Power voltage: AC 110 – 120 V or AC 220 – 240 V, 50/60Hz IEC standard 3P inlet type
- Rated power consumption: HIGH mode, KT170: 80 W, HIGH mode, EL34: 71 W, LOW mode, 6V6: 36 W
- Dimensions: 252(W) x 286(H) x 286(D) mm (with safety cover, incl. projections)
- Weight: Approx. 6,6 kg (assembled, excluding tubes and AC cord)

ELEKIT's tube and hybrid amplifier kits are aimed at people who want to understand and build the heart of their audio system with their own hands, not just buy it ready-made. The Japanese manufacturer provides a detailed, step-by-step assembly manual and a pre-etched, labelled PCB with every kit, so it can be assembled safely without any electronics background - most models only need a screwdriver and pliers, no soldering required. The finished amplifier's power, distortion and noise figures are documented by measurement, so you know exactly what to expect at the listening position. ELEKIT and its related accessory/upgrade kits (upgrade transformers, enclosures, replacement pots and knobs) form a modular system: a base amplifier kit can keep being improved years after purchase - for example with a better output transformer, a precision volume pot, or premium enclosure parts - without replacing the whole unit. This results in a system that keeps its value and can be expanded over time. Smaller accessories - enclosure parts, knobs, feet, pot replacements - typically bolt straight onto an amplifier you already own with nothing more than a screwdriver, so the look and feel of an older ELEKIT build can be refreshed without touching the internal circuitry at all.

ELEKIT's Japanese DIY audio kits have been known for decades for their precise manufacturing and well-documented, clearly explained assembly instructions - most models can be built in a few hours without soldering.

Package weight: approx. 7,7 kg. GTIN: 4952682108726.